Bonded metal product

Abstract

A bonded metal product constituted by bonding a first metal workpiece and a second metal workpiece. Metal microparticles formed from metal having a value for oxidation-reduction potential positively larger than H 2 are scattered in the crystal grain boundaries of either or both of the first metal workpiece and the second metal workpiece. In addition, metal bonding is formed between metal originating in the first metal workpiece and metal originating in the second metal workpiece in the bonding interface for the first metal workpiece and the second metal workpiece. Furthermore, the mental microparticles and oxygen are not present in the bonding interface.

1 . A bonded metal article comprising a first metal workpiece and a second metal workpiece bonded together, wherein
 one the first metal workpiece and the second metal workpiece is an iron-based alloy, and another is an aluminum alloy,   fine metal particles of silver are dispersed in crystal grain boundaries in at least one of the first metal workpiece and the second metal workpiece,   a metallic bond is formed between a metal in the first metal workpiece and a metal in the second metal workpiece at a bonding interface between the first metal workpiece and the second metal workpiece, and   in the bonding interface, a peak concerning the metal is not present in an in-depth profile of the fine metal particles measured by an energy dispersive X-ray spectroscopic analysis (EDX), and a peak concerning oxygen is not present in an in-depth profile of oxygen measured by a microspectroscopic analysis.   
     
     
         2 . The bonded metal article according to  claim 1 , wherein the bonded metal article has a gradient composition that an amount of the fine metal particles is larger in a crystal grain boundary closer to the bonding interface and is reduced as a distance from the bonding interface increases. 
     
     
         3 . The bonded metal article according to  claim 1 , wherein the metal contained in the fine metal particles has an oxygen adsorbability. 
     
     
         4 . The bonded metal according to  claim 1 , wherein
 the fine metal particles are dispersed in the crystal grain boundaries in the workpiece of the aluminum alloy in the first metal workpiece or the second metal workpiece, and   an intermetallic compound is generated from the metal in the first metal workpiece and the metal in the second metal workpiece due to the metallic bond at the bonding interface between the first metal workpiece and the metal in the second metal workpiece.   
     
     
         5 . The bonded metal article according to  claim 1 , wherein the bonding interface has a thickness of 0.1 to 1.8 μm. 
     
     
         6 . The bonded metal article according to  claim 5 , wherein the bonding interface has a thickness of 0.3 to 1.6 μm. 
     
     
         7 . The bonded metal article according to  claim 6 , wherein the bonding interface has a thickness of 0.5 to 1.3 μm. 
     
     
         8 . (canceled) 
     
     
         9 . A method for producing a bonded metal article, wherein the bonded metal article contains a first metal workpiece of one of an iron-based alloy and an aluminum alloy and a second metal workpiece of another of the iron-based alloy and the aluminum alloy, bonded together, fine metal particles of silver are dispersed in crystal grain boundaries in at least one of the first metal workpiece and the second metal workpiece, a metallic bond is formed between a metal in the first metal workpiece and a metal in the second metal workpiece at a bonding interface between the first metal workpiece and the second metal workpiece, in the bonding interface, a peak concerning the metal is not present in an in-depth profile of the fine metal particles measured by an energy dispersive X-ray spectroscopic analysis (EDX), a peak concerning oxygen is not present in an in-depth profile of oxygen measured by a microspectroscopic analysis, and the method comprises the steps of:
 applying the fine metal particles of silver to at least one of the first metal workpiece and the second metal workpiece,   fixing one of the first metal workpiece and the second metal workpiece to a first rotary holder, fixing another of the first metal workpiece and the second metal workpiece to a second rotary holder, and arranging the first metal workpiece and the second metal workpiece so that a surface to which the fine metal particles are applied faces the first or second metal workpiece, and   rotationally actuating the first rotary holder and the second rotary holder, and bringing the first metal workpiece and the second metal workpiece closer to each other into sliding contact with each other.   
     
     
         10 . (canceled) 
     
     
         11 . The method according to  claim 9 , wherein
 the silver particles are applied in a form of a silver paste, and   the silver paste is prepared by dispersing the silver particles in a dispersion medium so that an exposed area of the silver particles is 5.8×10 12  m 2 /g or more.   
     
     
         12 . A method for producing a bonded metal article ( 10 ), wherein the bonded metal article contains a first metal workpiece of one of an iron-based alloy and an aluminum alloy and a second metal workpiece of another of the iron-based alloy and the aluminum alloy, bonded together, fine metal particles of silver are dispersed in crystal grain boundaries in at least one of the first metal workpiece and the second metal workpiece, a metallic bond is formed between a metal in the first metal workpiece and a metal in the second metal workpiece at a bonding interface between the first metal workpiece and the second metal workpiece, in the bonding interface, a peak concerning the metal is not present in an in-depth profile of the fine metal particles measured by an enemy dispersive X-ray spectroscopic analysis (EDX), a peak concerning oxygen is not present in an in-depth profile of oxygen measured by a microspectroscopic analysis, and the method comprises the steps of:
 applying the fine metal particles of silver to at least one of the first metal workpiece and the second metal workpiece,   stacking the first metal workpiece and the second metal workpiece so that a surface to which the fine metal particles are applied faces the first or second metal workpiece to form an overlapping portion, and   bringing an ultrasonic horn into contact with the overlapping portion, and thereafter, transmitting a vibration by an ultrasonic wave output from the ultrasonic horn to the fine metal particles and contact surfaces of the first metal workpiece and the second metal workpiece while applying a load in a direction that the contact surfaces are brought closer to each other.   
     
     
         13 . The method according to  claim 12 , wherein
 the load applied to the contact surfaces has a magnitude of 30 to 50 MPa, and   the ultrasonic wave output from the ultrasonic horn has an intensity of 900 to 3000 W.   
     
     
         14 . (canceled) 
     
     
         15 . The method according to  claim 12 , wherein
 the silver particles are applied in a form of a silver paste, and   the silver paste is prepared by dispersing the silver particles in a dispersion medium so that an exposed area of the silver particles is 5.8×10 12  m 2 /g or more.